Push-to-talk (PTT) platforms involve providing PTT functionality (e.g., call group management, call origination, call transmittal, talk-back call termination, floor management, filtering, etc.) through PTT clients on client devices. The client devices may be referred to generally as user equipment (UE). The PTT functions may be performed by one or more servers, and communications between the client devices and the servers may be performed over a telecommunications network (e.g., a carrier network).
In some situations, particularly when one or more of the client devices are located outside a coverage area of a telecommunications network, direct mode communications may be used for the client devices to participate in PTT functions. For example, a first client device may use direct mode communications to communicate with a second client device (referred to as a relay), which bridges the first client device to a telecommunications network and/or other client devices. Various mechanisms for enabling client devices to act as relays using direct mode communications are defined in a Mission Critical Push-to-Talk (MCPTT) standard by the Third Generation Partnership Project (3GPP). However, gaps in the standard exist in how to handle multiple relays within range of a single client device, improving signaling efficiencies for group communications between a plurality of client devices and a relay, extending the range of relays, and the like.
Accordingly, there is a need for a systems and methods for direct mode PTT communication protocols.
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The apparatus and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.